U.S. patent application number 17/254310 was filed with the patent office on 2021-04-22 for main circuit of traction system and control method therefor and rail vehicle.
This patent application is currently assigned to ZHUZHOU CRRC TIMES ELECTRIC CO., LTD.. The applicant listed for this patent is ZHUZHOU CRRC TIMES ELECTRIC CO., LTD.. Invention is credited to Chaolu CHEN, Wenguang CHEN, Xinjian CHEN, Zhengliang GAO, Anhui JI, Xiong LIU, Rong MOU, Long WANG, Haobin XIONG, Nannan XU, Jun YANG, Mingliang ZENG, Bin ZHANG, Dongpo ZHU.
Application Number | 20210114466 17/254310 |
Document ID | / |
Family ID | 1000005341974 |
Filed Date | 2021-04-22 |
United States Patent
Application |
20210114466 |
Kind Code |
A1 |
WANG; Long ; et al. |
April 22, 2021 |
MAIN CIRCUIT OF TRACTION SYSTEM AND CONTROL METHOD THEREFOR AND
RAIL VEHICLE
Abstract
A method for controlling a main circuit of a traction system is
provided. The method includes: under a braking condition,
controlling a protection module to be turned off; controlling the
protection module to be turned on and monitoring a first current
detected by a first current sensor in a case that a rail vehicle
runs on a charged third rail; and controlling the protection module
to be turned off and monitoring whether the rail vehicle runs on a
charged third rail in a case that the first current is less than a
first preset current.
Inventors: |
WANG; Long; (Zhuzhou, Hunan,
CN) ; CHEN; Xinjian; (Zhuzhou, Hunan, CN) ;
ZHANG; Bin; (Zhuzhou, Hunan, CN) ; CHEN;
Wenguang; (Zhuzhou, Hunan, CN) ; CHEN; Chaolu;
(Zhuzhou, Hunan, CN) ; MOU; Rong; (Zhuzhou, Hunan,
CN) ; JI; Anhui; (Zhuzhou, Hunan, CN) ; LIU;
Xiong; (Zhuzhou, Hunan, CN) ; XU; Nannan;
(Zhuzhou, Hunan, CN) ; YANG; Jun; (Zhuzhou, Hunan,
CN) ; GAO; Zhengliang; (Zhuzhou, Hunan, CN) ;
XIONG; Haobin; (Zhuzhou, Hunan, CN) ; ZENG;
Mingliang; (Zhuzhou, Hunan, CN) ; ZHU; Dongpo;
(Zhuzhou, Hunan, CN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ZHUZHOU CRRC TIMES ELECTRIC CO., LTD. |
Zhuzhou, Hunan |
|
CN |
|
|
Assignee: |
ZHUZHOU CRRC TIMES ELECTRIC CO.,
LTD.
Zhuzhou, Hunan
CN
|
Family ID: |
1000005341974 |
Appl. No.: |
17/254310 |
Filed: |
November 22, 2018 |
PCT Filed: |
November 22, 2018 |
PCT NO: |
PCT/CN2018/116883 |
371 Date: |
December 21, 2020 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B61H 9/04 20130101; B60L
9/18 20130101; B61L 25/065 20130101; B60M 1/30 20130101; B60L 7/16
20130101 |
International
Class: |
B60L 9/18 20060101
B60L009/18; B60L 7/16 20060101 B60L007/16; B60M 1/30 20060101
B60M001/30; B61H 9/04 20060101 B61H009/04; B61L 25/06 20060101
B61L025/06 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 21, 2018 |
CN |
201810644334.0 |
Claims
1. A method for controlling a main circuit of a traction system,
comprising: under a braking condition, controlling a protection
module to be turned off; controlling the protection module to be
turned on and monitoring a first current detected by a first
current sensor in a case that a rail vehicle runs on a charged
third rail; and controlling the protection module to be turned off
and monitoring whether the rail vehicle runs on a charged third
rail in a case that the first current is less than a first preset
value.
2. The method according to claim 1, further comprising: under a
traction condition or a coasting condition, controlling the
protection module to be turned off; controlling the protection
module to be turned on and monitoring a first current detected by
the first current sensor, in a case that the rail vehicle runs on a
charged third rail; and controlling the protection module to be
turned off and monitoring whether the rail vehicle runs on a
charged third rail in a case that the first current is less than
the first preset value.
3. The method according to claim 1, wherein the fact that the rail
vehicle runs on a charged third rail is determined by a voltage
sensor detecting a voltage greater than a second preset value.
4. A main circuit of a traction system, comprising: a current
collector; a first current sensor; a voltage sensor; a protection
module; a support capacitor; a current conversion module; and a
processor, wherein the processor is configured to execute a
computer program to perform the method for controlling a main
circuit of a traction system according to claim 1.
5. The main circuit of a traction system according to claim 4,
wherein the protection module comprises a first controllable
switch, a first unidirectional conductive component, a second
controllable switch and a second unidirectional conductive
component, wherein a first end of the first controllable switch is
connected to a first end of the first unidirectional conductive
component, as a first end of the protection module; a second end of
the first controllable switch and a second end of the first
unidirectional conductive component are both connected to a first
end of the second controllable switch and a first end of the second
unidirectional conductive component are; and a second end of the
second controllable switch is connected to a second end of the
second unidirectional conductive component, as a second end of the
protection module, wherein a direction in which the first
unidirectional conductive component outputs a current is opposite
to a direction in which the second unidirectional conductive
component outputs a current.
6. The main circuit of a traction system according to claim 5,
further comprising a circuit breaker configured to control the main
circuit of a traction system to be turned on or turned off, wherein
a first end of the circuit breaker is connected to a second end of
the first current sensor; and a second end of the circuit breaker
is connected to the first end of the protection module and a first
end of the voltage sensor.
7. The main circuit of a traction system according to claim 6,
further comprising an inductor configured to perform filtering
together with the support capacitor, wherein a first end of the
inductor is connected to the second end of the protection module;
and a second end of the inductor is connected to a first end of the
support capacitor and a first end of the current conversion
module.
8. The main circuit of a traction system according to claim 7,
further comprising a second current sensor, wherein a first end of
the second current sensor is connected to a second end of the
voltage sensor, a second end of the current conversion module and a
second end of the support capacitor; a second end of the second
current sensor is grounded; and an output end of the second current
sensor is connected to the processor, wherein the processor is
further configured to control the circuit breaker to be turned off
in a case that a difference between a second current detected by
the second current sensor and the first current is greater than a
preset difference.
9. The main circuit of a traction system according to claim 5,
wherein at least one of the first controllable switch and the
second controllable switch is implemented by an insulated gate
bipolar transistor IGBT, wherein in a case that the first
controllable switch is implemented by the IGBT, a parasitic diode
of the first controllable switch serves as the first unidirectional
conductive component; and in a case that the second controllable
switch is implemented by the IGBT, a parasitic diode of the second
controllable switch serves as the second unidirectional conductive
component.
10. A rail vehicle, comprising the main circuit of a traction
system according to claim 4.
Description
[0001] The present application claims priority to Chinese Patent
Application No. 201810644334.0, titled "MAIN CIRCUIT OF TRACTION
SYSTEM AND CONTROL METHOD THEREFOR AND RAIL VEHICLE", filed on Jun.
21, 2018 with the China National Intellectual Property
Administration, which is incorporated herein by reference in its
entirety.
FIELD
[0002] The present disclosure relates to the technical field of
rail vehicles, and in particular to a method for controlling a main
circuit of a traction system, a main circuit of a traction system
and a rail vehicle.
BACKGROUND
[0003] Currently, a considerable number of rail vehicles are
powered by electrical energy collected by a third rail. Since a
third rail has different power supply divisions and a rail has
branches, the third rail cannot be continuous and has an
electricity gap (rail gap). Further, there are many uncharged third
rails (dead rails) due to faults or construction by workers.
[0004] Reference is made to FIG. 2, which is a schematic structural
diagram of a main circuit of a traction system in the conventional
technology. The main circuit of a traction system includes a
current collector A, a first current sensor LH1, a voltage sensor
VH, a protection module, a support capacitor C, a current
conversion module and a processor. The protection module includes a
charging contactor KM1, a charging resistor R and a short-circuit
contactor KM2. A first end of the charging contactor KM1 is
connected to a first end of the short-circuit contactor KM2, as a
first end of the protection module. A second end of the charging
contactor KM1 is connected to a first end of the charging resistor
R. A second end of the charging resistor R is connected to a second
end of the short-circuit contactor KM2, as a second end of the
protection module.
[0005] In the conventional technology, the processor controls the
protection module to be turned off during a braking condition of a
rail vehicle in order to prevent electrical energy generated by a
traction motor from being fed back to a dead rail via the current
collector. In this case, even if the third rail is capable of
collecting electrical energy, electrical energy generated by the
traction motor cannot be fed back to the third rail and has to be
consumed by a braking resistor, resulting in waste of the
electrical energy.
[0006] Therefore, how to solve the above technical problems is
required to be solved by those skilled in the art currently.
SUMMARY
[0007] A method for controlling a main circuit of a traction system
is provided according to the present disclosure, such that
electrical energy generated by braking a traction motor can be
safely fed back to a charged third rail, thereby saving the
electrical energy. In addition, a main circuit of a traction system
and a rail vehicle are further provided according to the present
disclosure, such that electrical energy generated by braking a
traction motor can be safely fed back to a charged third rail,
thereby saving the electrical energy.
[0008] To solve the above technical problems, a method for
controlling a main circuit of a traction system is provided
according to the present disclosure. The method includes: under a
braking condition, controlling a protection module to be turned
off; controlling the protection module to be turned on and
monitoring a first current detected by a first current sensor in a
case that a rail vehicle runs on a charged third rail; and
controlling the protection module to be turned off and monitoring
whether the rail vehicle runs on a charged third rail in a case
that the first current is less than a first preset value.
[0009] Preferably, the method further includes: under a traction
condition or a coasting condition, controlling the protection
module to be turned off; controlling the protection module to be
turned on and monitoring a first current detected by the first
current sensor in a case that the rail vehicle runs on a charged
third rail; and controlling the protection module to be turned off
and monitoring whether the rail vehicle runs on a charged third
rail in a case that the first current is less than the first preset
value.
[0010] Preferably, the rail vehicle running on a charged third rail
includes a case that a voltage detected by a voltage sensor is
greater than a second preset value, where the controlling the
protection module to be turned off and monitoring whether the rail
vehicle runs on a charged third rail in a case that the first
current is less than a first preset value includes: controlling the
protection module to be turned off and monitoring the voltage in
the case that the first current is less than the first preset
value.
[0011] To solve the above technical problems, a main circuit of a
traction system is further provided according to the present
disclosure. The main circuit of a traction system includes a
current collector, a first current sensor, a voltage sensor, a
protection module, a support capacitor, a current conversion module
and a processor. The processor is configured to execute a computer
program to perform the method for controlling a main circuit of a
traction system according to any one of the above.
[0012] Preferably, the protection module includes a first
controllable switch, a first unidirectional conductive component, a
second controllable switch and a second unidirectional conductive
component. A first end of the first controllable switch is
connected to a first end of the first unidirectional conductive
component, as a first end of the protection module. A second end of
the first controllable switch and a second end of the first
unidirectional conductive component are both connected to a first
end of the second controllable switch and a first end of the second
unidirectional conductive component. A second end of the second
controllable switch is connected to a second end of the second
unidirectional conductive component, as a second end of the
protection module. A direction in which the first unidirectional
conductive component outputs a current is opposite to a direction
in which the second unidirectional conductive component outputs a
current.
[0013] Preferably, the main circuit of a traction system further
includes a circuit breaker. A first end of the circuit breaker is
connected to a second end of the first current sensor. A second end
of the circuit breaker is connected to the first end of the
protection module and a first end of the voltage sensor. The
circuit breaker is configured to control the main circuit of a
traction system to be turned on or turned off.
[0014] Preferably, the main circuit of a traction system further
includes an inductor. A first end of the inductor is connected to
the second end of the protection module. A second end of the
inductor is connected to a first end of the support capacitor and a
first end of the current conversion module. The inductor is
configured to perform filtering together with the support
capacitor.
[0015] Preferably, the main circuit of a traction system further
includes a second current sensor. A first end of the second current
sensor is connected to a second end of the voltage sensor, a second
end of the current conversion module and a second end of the
support capacitor. A second end of the second current sensor is
grounded. An output end of the second current sensor is connected
to the processor. The processor is further configured to control
the circuit breaker to be turned off in a case that a difference
between a second current detected by the second current sensor and
the first current is greater than a preset difference.
[0016] Preferably, at least one of the first controllable switch
and the second controllable switch is implemented by an insulated
gate bipolar transistor IGBT. In a case that the first controllable
switch is implemented by the IGBT, a parasitic diode of the first
controllable switch serves as the first unidirectional conductive
component. In a case that the second controllable switch is
implemented by the IGBT, a parasitic diode of the second
controllable switch serves as the second unidirectional conductive
component.
[0017] To solve the above technical problems, a rail vehicle is
further provided according to the present disclosure. The rail
vehicle includes the main circuit of a traction system according to
any one of the above.
[0018] A method for controlling a main circuit of a traction system
is provided according to the present disclosure. The method
includes: under a braking condition, controlling a protection
module to be turned off; controlling the protection module to be
turned on and monitoring a first current detected by a first
current sensor in a case that a rail vehicle runs on a charged
third rail; and controlling the protection module to be turned off
and monitoring whether the rail vehicle runs on a charged third
rail in a case that the first current is less than a first preset
value.
[0019] It can be seen that in the present disclosure, in a case
that a rail vehicle operates under a braking condition, the
protection module is controlled to be turned off first. In a case
that the rail vehicle runs on a charged third rail, the protection
module is controlled to be turned on, so that electrical energy
generated by a traction motor can be safely fed back to the charged
third rail via the current conversion module. In addition, a
current detected by the first current sensor is monitored. A case
that the current is less than a first preset value indicates that
the third rail is uncharged or that the third rail is incapable of
collecting electrical energy. In this case, the protection module
is controlled to be turned off. Therefore, the electrical energy
generated by the traction motor can be prevented from being fed
back to the uncharged third rail so as to avoid accidents. Further,
the electrical energy generated by braking the traction motor can
be fed back to the charged third rail for utilization, thereby
saving the electrical energy.
[0020] A main circuit of a traction system and a rail vehicle are
further provided according to the present disclosure, and have the
same beneficial effects as the above method.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] In order to illustrate technical solutions in embodiments of
the present disclosure more clearly, drawings to be used in the
description of the embodiments or the conventional technology are
introduced simply hereinafter. It is apparent that the drawings
described below show only some embodiments of the present
disclosure. For those skilled in the art, other drawings may be
obtained based on the provided drawings without any creative
work.
[0022] FIG. 1 is a schematic flowchart of a method for controlling
a main circuit of a traction system according to the present
disclosure;
[0023] FIG. 2 is a schematic structural diagram of a main circuit
of a traction system according to the conventional technology;
[0024] FIG. 3 is a schematic structural diagram of a main circuit
of a traction system according to an embodiment of the present
disclosure;
[0025] FIG. 4 is a schematic structural diagram of a main circuit
of a traction system according to another embodiment of the present
disclosure; and
[0026] FIG. 5 is a schematic structural diagram of a main circuit
of a traction system according to another embodiment of the present
disclosure.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0027] A method for controlling a main circuit of a traction system
is provided according to the present disclosure, such that
electrical energy generated by braking a traction motor can be
safely fed back to a charged third rail, thereby saving the
electrical energy. In addition, a main circuit of a traction system
and a rail vehicle are further provided according to the present
disclosure, such that electrical energy generated by braking a
traction motor can be safely fed back to a charged third rail,
thereby saving the electrical energy.
[0028] In order to make objects, technical solutions and advantages
of the embodiments of the present disclosure clearer, the technical
solutions in the embodiments of the present disclosure are
described clearly and completely in conjunction with the drawings
in the embodiments of the disclosure hereinafter. It is apparent
that the described embodiments are only some rather than all
embodiments of the present disclosure. All other embodiments
obtained by those skilled in the art based on the embodiments of
the present disclosure without any creative work fall within the
protection scope of the present disclosure.
[0029] Reference is made to FIG. 1, which is a schematic flowchart
of a method for controlling a main circuit of a traction system
according to the present disclosure. The method includes the
following steps S1 to S3.
[0030] In step S1, under a braking condition, a protection module 3
is controlled to be turned off.
[0031] Under the braking condition, the protection module 3 is
controlled to be turned off first, so as to prevent electrical
energy generated by a traction motor under the braking condition
from being fed back to a uncharged third rail via a current
conversion module 2 and the protection module 3, thereby avoiding
accidental damage to a worker on the uncharged third rail.
[0032] The protection module 3 is configured to control a circuit
to be turned on or turned off. The protection module 3 may be in
various forms and may be arranged at various positions in the
circuit, for example, as shown in FIG. 2. Forms and positions of
the protection module 3 are not limited in the embodiments of the
present disclosure.
[0033] In step S2, in a case that a rail vehicle runs on a charged
third rail, the protection module 3 is controlled to be turned on,
and a first current detected by a first current sensor LH1 is
monitored.
[0034] In the case that the rail vehicle runs on a charged third
rail, the electrical energy generated by the traction motor can be
safely fed back to the third rail. After the protection module 3 is
controlled to be turned on, alternating current electricity
generated by the traction motor is rectified by the current
conversion module 2 and then is fed back to the charged third rail
via the protection module 3. The third rail collects the
alternating current electricity to supply other rail vehicles
running on the third rail. Therefore, it is unnecessary to consume,
by a braking resistor, the electrical energy generated by braking
the traction motor, thereby improving utilization of electrical
energy and saving the electrical energy.
[0035] The first current detected by the first current sensor LH1
is a current fed back to the third rail by the traction motor. This
current is monitored to facilitate the following operations.
[0036] In step S3, in a case that the first current is less than a
first preset value, the protection module 3 is controlled to be
turned off, and it is monitored whether the rail vehicle runs on a
charged third rail.
[0037] In an embodiment of the present disclosure, the case that
the first current is less than the first preset value may indicate
that the rail vehicle runs on an uncharged third rail, that is, a
dead rail, or indicate that the third rail is incapable of
collecting electrical energy. In this case, the protection module 3
is controlled to be turned off so as to prevent the electrical
energy generated by the traction motor from being fed back to the
dead rail, thereby avoiding accidental damage to a worker on the
dead rail. In addition, it is further monitored whether the rail
vehicle runs on a charged third rail, so as to control the
protection module 3 to be turned on to feed the electrical energy
back to a charged third rail when the rail vehicle runs on the
charged third rail.
[0038] The first preset value may have a value approximating zero.
In a case that the rail vehicle rans in a rail gap or runs on a
dead rail, or a charged third rail is capable of collecting
electrical energy, the first current first approximates zero first
and then decreases to zero. When the first current approximates
zero, the protection module 3 is controlled to be turned off, so as
to further improve safety of the main circuit of a traction system,
thereby preventing the electrical energy from being fed back to the
dead rail.
[0039] In addition, in a case that the protection module 3 is
turned off, the electrical energy generated by the traction motor
may be consumed by the braking resistor. A braking unit may be
integrated in the current conversion module 2. The braking unit may
be a chopper circuit. The chopper circuit is connected to the
braking resistor and is configured to control the braking resistor
to consume the electrical energy generated by the traction
motor.
[0040] A method for controlling a main circuit of a traction system
is provided according to the present disclosure. The method
includes: under a braking condition, controlling a protection
module to be turned off; controlling the protection module to be
turned on and monitoring a first current detected by a first
current sensor in a case that a rail vehicle runs on a charged
third rail; and controlling the protection module to be turned off
and monitoring whether the rail vehicle runs on a charged third
rail in a case that the first current is less than a first preset
value.
[0041] It can be seen that in the present disclosure, in a case
that a rail vehicle operates under a braking condition, the
protection module is controlled to be turned off first. In a case
that the rail vehicle runs on a charged third rail, the protection
module is controlled to be turned on, so that electrical energy
generated by a traction motor can be safely fed back to the charged
third rail via the current conversion module. Further, a current
detected by the first current sensor is monitored. A case that the
current is less than a first preset value indicates that the third
rail is uncharged or that the third rail is incapable of collecting
electrical energy. In this case, the protection module is
controlled to be turned off. Therefore, the electrical energy
generated by the traction motor can be prevented from being fed
back to the uncharged third rail so as to avoid accidents. Further,
the electrical energy generated by braking the traction motor can
be fed back to the charged third rail for utilization, thereby
saving electrical energy.
[0042] Based on the above embodiments, in a preferred embodiment,
the method further includes: under a traction condition or a
coasting condition, controlling the protection module to be turned
off; controlling the protection module to be turned on and
monitoring a first current detected by the first current sensor in
a case that the rail vehicle runs on a charged third rail; and
controlling the protection module to be turned off and monitoring
whether the rail vehicle runs on a charged third rail in a case
that the first current is less than the first preset value.
[0043] In an embodiment of the present disclosure, in a case that
the rail vehicle operates under a traction condition or a coasting
condition, the protection module is controlled to be turned off. In
the case that the rail vehicle runs on the charged third rail, the
protection module is controlled to be turned on, and the first
current detected by the first current sensor is monitored. In the
case that the rail vehicle operates under the traction condition,
electrical energy in the third rail can be supplied to the traction
motor via the protection module that is turned on. In the case that
the rail vehicle operates under the coasting condition, the
electrical energy in the third rail can also be supplied to the
traction motor via the protection module that is turned on, to keep
the traction motor charged. In the case that the first current is
less than the first preset value, the protection module is
controlled to be turned off and it is monitored whether the rail
vehicle runs on a charged third rail, so as to prevent electrical
energy in the support capacitor from being fed back to the
uncharged third rail, thereby avoiding accidental damage to a
worker. In the embodiment of the present disclosure, the protection
module is controlled under the traction condition or the coasting
condition, so that the electrical energy from the third rail can be
utilized effectively. Further, the electrical energy in the support
capacitor can be prevented from being fed back to an uncharged
third rail, thereby avoiding accidents.
[0044] In a preferred embodiment, the rail vehicle running on a
charged third rail includes a case that a voltage detected by a
voltage sensor VH is greater than a second preset value. The
protection module 3 being controlled to be turned off and whether
the rail vehicle runs on a charged third rail being monitored in a
case that the first current is less than a first preset value
includes: the protection module 3 being controlled to be turned off
and the voltage being monitored in the case that the first current
is less than the first preset value.
[0045] In an embodiment of the present disclosure, the rail vehicle
running on the charged third rail may be determined as the case
that the voltage detected by the voltage sensor VH in FIG. 2 is
greater than the second preset value. In this case, whether the
rail vehicle runs on a charged third rail can be determined by
using the voltage sensor VH in the conventional technology without
an additional component, thereby reducing costs.
[0046] In addition to the above technical solutions, whether the
rail vehicle runs on a charged third rail may also be determined in
another manner. For example, a voltage detection device may be
arranged on the third rail. A processor 1 may acquire a charged
state of the third rail from the voltage detection device, so as to
perform corresponding operations. Alternatively, a position at
which the rail vehicle is currently located may be determined based
on a starting position, a running speed and a running route of the
rail vehicle. Then, whether the third rail is a charged third rail
may be determined based on a pre-stored correspondence between a
position of the rail vehicle and the charged state of the third
rail. Whether the rail vehicle runs on a charged third rail may
also be determined in other manners, which are not limited
thereto.
[0047] Reference is made to FIG. 3, which is a schematic structural
diagram of a main circuit of a traction system according to the
present disclosure. The main circuit of a traction system includes
a current collector A, a first current sensor LH1, a voltage sensor
VH, a protection module 3, a support capacitor C, a current
conversion module 2 and a processor 1. The processor 1 is
configured to execute a computer program to perform the method for
controlling a main circuit of a traction system according to any
one of the above embodiments.
[0048] The main circuit of a traction system may include two
current collectors A, and two first current sensors LH1
accordingly. The two collectors A may be both connected to a power
supply line. Each of the two collectors A is provided with a first
current sensors LH1 at an input side of the current collector A, to
detect a current of the current collector A. Therefore, a case that
a rail vehicle runs in a rail gap or runs on a dead rail may be
determined as a case that currents detected by the two first
current sensors LH1 decrease to zero successively, thereby
improving safety. Further, transmission effects of the current can
be improved with the two current collectors A.
[0049] Alternatively, the main circuit of a traction system may
include two current collectors A and one first current sensor LH1,
which is not limited in the embodiment of the present
disclosure.
[0050] In an embodiment of the present disclosure, a capacitor may
be connected in series between a grounded side and a ground end,
such that electromagnetic interference of the circuit can be
reduced, and therefore electromagnetic interference received by
components in the main circuit of a traction system is small.
[0051] The main circuit of a traction system according to the
embodiment of the present disclosure may refer to the embodiments
of the above method, and is not described in detail here.
[0052] Based on the above embodiments, in a preferred embodiment,
the protection module 3 includes a first controllable switch Q1, a
first unidirectional conductive component D1, a second controllable
switch Q2 and a second unidirectional conductive component D2.
[0053] A first end of the first controllable switch Q1 is connected
to a first end of the first unidirectional conductive component D1,
as a first end of the protection module 3. A second end of the
first controllable switch Q1 and a second end of the first
unidirectional conductive component D1 are both connected to a
first end of the second controllable switch Q2 and a first end of
the second unidirectional conductive component D2. A second end of
the second controllable switch Q2 is connected to a second end of
the second unidirectional conductive component D2, as a second end
of the protection module 3. A direction in which the first
unidirectional conductive component D1 outputs a current is
opposite to a direction in which the second unidirectional
conductive component D2 outputs a current
[0054] In the conventional technology, a charging contactor and a
short-circuit contactor in the protection module 3 each have an
electrical life of tens of thousands of times, and are turned on
and off a large number of times every day, resulting in great
reduction in a service life of the charging contactor and a service
life of the short-circuit contactor. According to the embodiment of
the present disclosure, a service life of the first controllable
switch Q1 is not affected by the number of times that the first
controllable switch Q1 is turned on and off, and a service life of
the second controllable switch Q2 is not affected by the number of
times that the second controllable switch Q2 is turned on and off.
The first controllable switch Q1 and the second controllable switch
Q2 according to the embodiment of the present disclosure each have
a service life of numerous years, for example, ten years.
Therefore, the protection module 3 according to the embodiment of
the present disclosure has a long service life, thereby reducing
costs. Further, it is unnecessary to repeatedly replace and
maintain components in the protection module 3, thereby reducing
labor costs.
[0055] Considering the application scenarios of the embodiments of
the present disclosure, each of the first controllable switch Q1
and the second controllable switch Q2 may be implemented by a
high-power controllable switch.
[0056] In a preferred embodiment, the main circuit of a traction
system further includes a circuit breaker HB. A first end of the
circuit breaker BB is connected to a second end of the first
current sensor LH1. A second end of the circuit breaker BB is
connected to the first end of the protection module 3 and a first
end of the voltage sensor VH. The circuit breaker HB is configured
to control the main circuit of a traction system to be turned on or
turned off.
[0057] During operation of the rail vehicle, the main circuit of a
traction system is required to be turned off in many cases. For
example, if it is detected that the processor 1 cannot successfully
control the first controllable switch Q1 and/or the second
controllable switch Q2 to be turned on or off in a case that the
rail vehicle runs operates in a traction condition, a coasting
condition or a braking condition, the circuit breaker HB is
controlled to be turned off to prevent, for example, the electrical
energy from being fed back to a dead rail so as to avoid accidents,
thereby increasing the safety of the main circuit of a traction
system.
[0058] In addition to the above cases, the circuit breaker HB may
also be controlled to be turned off in a case that a component,
such as the current conversion module 2 or a motor, has a fault, so
as to avoid accidents.
[0059] The circuit breaker HB may be a high-speed circuit breaker
with a fast respond speed, thereby further improving safety of the
main circuit of a traction system.
[0060] In addition to the above arrangement, the circuit breaker HB
may also be arranged between the current collector A and the first
current sensor LH1. One end of the circuit breaker BB is connected
to the current collector A, and the other end of the circuit
breaker BB is connected to the first current sensor LH1.
Alternatively, the circuit breaker BB may be arranged between the
voltage sensor VH and the protection module 3. The first end of the
circuit breaker BB is connected to the first end of the voltage
sensor VH, and the second end of the circuit breaker BB is
connected to the first end of the protection module 3.
[0061] The processor 1 is further configured to control the circuit
breaker BB to be turned off in a case that the first current
detected by the first current sensor LH1 is greater than a third
preset value.
[0062] The first current sensor LH1 may detect the first current
supplied from the third rail to the traction motor. The case that
the first current is greater than the third preset value indicates
that a load of the traction motor is too high. In this case, the
circuit breaker HB may be controlled to be turned off, so as to
avoid damage to a related component and device.
[0063] In addition to the circuit breaker HB, the main circuit of a
traction system may further include a three position switch. The
three position switch is arranged between the first current sensor
LH1 and the circuit breaker HB. The three position switch may be
manipulated by a worker to operate in three gears, namely, a normal
power-on mode, an overhaul mode and a turn-off and maintenance
mode, which is convenient for the worker to control the circuit to
be turned off when the circuit requires an overhaul and
maintenance.
[0064] In a preferred embodiment, the main circuit of a traction
system further includes an inductor L. A first end of the inductor
L is connected to the second end of the protection module 3. A
second end of the inductor L is connected to a first end of the
support capacitor C and a first end of the current conversion
module 2. The inductor L is configured to perform filtering
together with the support capacitor C.
[0065] A filter formed by the inductor L and the support capacitor
C may filter out a clutter in direct current electricity
transmitted by the third rail, thereby enhancing anti-interference
performance of the circuit.
[0066] A type of the inductor L is not limited in the embodiment of
the present disclosure. For example, the inductor L may be a
choking inductor L.
[0067] There are many types of the current sensor, which are not
limited in the embodiments of the present disclosure.
[0068] In a preferred embodiment, the main circuit of a traction
system further includes a second current sensor LH2. A first end of
the second current sensor LH2 is connected to a second end of the
voltage sensor VH, a second end of the current conversion module 2
and a second end of the support capacitor C. A second end of the
second current sensor LH2 is grounded. An output end of the second
current sensor LH2 is connected to the processor 1. The processor 1
is further configured to control the circuit breaker BB to be
turned off in a case that a difference between a second current
detected by the second current sensor LH2 and the first current is
greater than a preset difference.
[0069] The second current sensor LH2 may detect the second current
flowing through a negative output line at the ground end of the
circuit. A case that the processor 1 determines that the difference
between the first current and the second current is greater than
the preset difference indicates that an electrical device between
the first current sensor LH1 and the second current sensor LH2 may
be short-circuited. In this case, the circuit breaker BB is
controlled to be turned off, which is convenient for the worker to
overhaul the circuit, thereby avoiding further damage.
[0070] A type of the second current sensor LH2 is not limited in
the embodiments of the present disclosure.
[0071] The preset difference may be determined based on experience,
which may be a difference between a current detected by the second
current sensor LH1 and a current detected by a third current sensor
LH2 under a normal condition.
[0072] In a preferred embodiment, at least one of the first
controllable switch Q1 and the second controllable switch Q2 may be
implemented by an IGBT (Insulated Gate Bipolar Transistor). In a
case that the first controllable switch Q1 is implemented by the
IGBT, a parasitic diode of the first controllable switch Q1 serves
as the first unidirectional conductive component D1. In a case that
the second controllable switch Q2 is implemented by the IGBT, a
parasitic diode of the second controllable switch Q2 serves as the
second unidirectional conductive component D2.
[0073] The IGBT has advantages of high withstand voltage, low
conduction voltage, fast switching speed and long service life.
[0074] In addition to the IGBT, at least one of the first
controllable switch Q1 and the second controllable switch Q2 may
also be implemented by other types of controllable switch, such as
a GTO (Gate Turn-Off Thyristor), a GTR (Giant Transistor), a MOSFET
(Metal-Oxide-Semiconductor Field-Effect Transistor), a power
field-effect transistor POWER MOSFET, an IGCT (integrated Gate
Commutated Transistor), an MCT (MOS Controlled Thyristor), and a
Static Induction Thyristor SITH, which are not limited in the
embodiments of the present disclosure.
[0075] In order to illustrate the embodiments of the present
disclosure better, reference is made to FIG. 4, which is a
schematic structural diagram of a main circuit of a traction system
according to another embodiment of the present disclosure. The main
circuit of a traction system includes a current collector A, a
first current sensor LH1, a circuit breaker HB, a second current
sensor LH2, a third current sensor LH3, a first controllable switch
Q1, a second controllable switch Q2, a first unidirectional
conductive component D1, a second unidirectional conductive
component D2, an inductor L, a support capacitor C, a current
conversion module 2, a voltage sensor VH and a processor 1.
[0076] In a case that the rail vehicle operates under the traction
condition, the processor 1 may, in response to a traction command,
control the first controllable switch Q1 to be turned on and the
second controllable switch Q2 to be turned off. Direct current
electricity in the third rail may be converted into direct current
electricity by the current conversion module 2, so as to supply
power to the traction motor. The current conversion module 2 may be
a traction converter, which inverts high-voltage direct current
electricity into alternating current electricity with an adjustable
voltage and an adjustable frequency, so as to supply power to the
traction motor.
[0077] Under the traction condition, in a case that the rail
vehicle runs in a rail gap or runs on a dead rail, the first
current detected by the first current sensor LH1 decreases to zero
because the rail vehicle runs away from the third rail with
high-voltage. The processor 1 controls the first controllable
switch Q1 and the second controllable switch Q2 to be turned off
immediately when determining that the first current detected by the
first current sensor LH1 is less than the first preset value (which
is a threshold set by the traction system in advance), that is,
when determining that the rail vehicle runs in a rail gap or runs
on a dead rail, so as to prevent high-voltage electricity of the
support capacitor C from being fed back to the dead rail. In
addition, it may be determined whether to turn off the current
conversion module 2 based on actual requirements of user.
[0078] In a case that the rail vehicle operates under a coasting
condition and the rail vehicle does not turn off the current
conversion module 2, the processor 1 may control the first
controllable switch Q1 to be turned on and the second controllable
switch Q2 to be turned off. The high-voltage direct current
electricity in the third rail is supplied to the traction motor via
the current collector A and the current conversion module 2. In a
case that the rail vehicle runs in a rail gap or runs on a dead
rail, the first current detected by the first current sensor LH1 is
equal to zero because the rail vehicle runs away from the third
rail with high-voltage. The processor 1 controls the first
controllable switch Q1 and the second controllable switch Q2 to be
turned off immediately when determining that the first current
detected by the first current sensor LH1 is less than the first
preset value, that is, when determining that the rail vehicle runs
in a rail gap or runs on a dead rail, so as to prevent high-voltage
electricity of the support capacitor C from being fed back to the
dead rail. In addition, it may be determined whether to turn off
the current conversion module 2 based on actual requirements of
user.
[0079] In a case that the rail vehicle operates under the coasting
condition and the rail vehicle turns off the current conversion
module 2, the processor 1 may control the first controllable switch
Q1 and the second controllable switch Q2 both to be turned off, so
as to prevent the high-voltage electricity of the support capacitor
C from being fed back to the dead rail.
[0080] When switching to the braking condition, the rail vehicle
first performs regenerative braking to convert mechanical energy of
the traction motor into electrical energy. The electrical energy is
rectified by the current conversion module 2 into direct current
electricity, and then is fed back to the third rail via the
inductor L. Whether the rail vehicle runs in a rail gap or runs on
a dead rail may also be determined by monitoring the first current
detected by the first current sensor LH1. However, different from
the traction condition, whether the rail vehicle runs in a rail gap
or runs on a dead rail may be determined the same as that under the
traction condition in a case that the third rail is capable of
collecting electrical energy. Whether the rail vehicle runs in a
rail gap or runs on a dead rail may be erroneously determined in a
case that the third rail is incapable of collecting electrical
energy. As a result, the rail vehicle cannot feed the electrical
energy generated from regenerative braking back to the third rail
after the third rail is capable of collecting electrical energy.
Therefore, the main circuit of a traction system under the braking
condition is controlled as follows.
[0081] When the rail vehicle switches to the braking condition, a
control system of the traction system immediately controls the
first controllable switch Q1 to be turned off. Then, it is
determined whether the voltage sensor VH detects a line voltage. In
a case that the voltage sensor VH detects the line voltage, the
second controllable switch Q2 is turned on, and the electrical
energy generated from regenerative braking is fed back to the third
rail via the second controllable switch Q2 and a diode connected in
paralleled with the first controllable switch Q1. In a case that
the rail vehicle runs in a rail gap or runs on a dead rail, or the
charged third rail is incapable of collecting electrical energy,
the first current detected by the first current sensor LH1
decreases to zero. The processor 1 controls the second controllable
switch Q2 to be turned off immediately when determining that the
first current detected by the first current sensor LH1 is less than
the first preset value, that is, when determining that the rail
vehicle runs in a rail gap or runs on a dead rail or the charged
third rail is incapable of collecting electrical energy. Then, the
processor 1 monitors whether the voltage detected by the voltage
sensor VH is greater than a second preset value. In a case that the
voltage detected by the voltage sensor VH is greater than the
second preset value, the second controllable switch Q2 is
controlled to be turned on at a fixed frequency. In addition, the
first current detected by the first current sensor LH1 is
monitored, and the above operations are repeated.
[0082] Accordingly, in a case that the rail vehicle runs on an
uncharged third rail and is required to switch to the traction
condition, the processor 1 may control the first controllable
switch Q1 to be turned on and the second controllable switch Q2 to
be turned off when determining that the voltage detected by the
voltage sensor VH is greater than the second preset value. The rail
vehicle switches to the traction condition.
[0083] The first controllable switch Q1 and the second controllable
switch Q2 may be integrated into the current conversion module 2.
In this way, a charging contactor, a charging resistor and a
short-circuit contactor in the conventional technology may be
omitted, so as to save space of a cabinet. In addition, the
processor 1 may be integrated into the current conversion module 2,
so as to further save space for wiring, which is of great
significance for weight reduction and structure optimization.
[0084] Reference is made to FIG. 5, which is a schematic structural
diagram of a main circuit of a traction system according to another
embodiment of the present disclosure. Based on the technical
solutions shown in FIG. 4, the main circuit of a traction system
shown in FIG. 5 further includes a diode D3. A cathode of the diode
D3 is connected to the second end of the protection module 3 and
the first end of the inductor L. An anode of the diode D3 is
connected to the first end of the second current sensor LH2, the
second end of the support capacitor C and the second end of the
current conversion module 2. When the support capacitor C is
initially charged before operation of the rail vehicle, the support
capacitor C may be charged, in coordination with a free-wheeling
circuit formed by the inductor L, the support capacitor C and the
diode D3, by controlling the first controllable switch Q1 to be
turned on or off.
[0085] There may be many types of the diode D3, such as a fast
recovery diode or a Schottky diode, which is not limited
herein.
[0086] A rail vehicle is further provided according to the present
disclosure. The rail vehicle includes the main circuit of a
traction system according to any one of the above embodiments.
[0087] For description of the rail vehicle according to the present
disclosure, reference may be made to the embodiments of the main
circuit of a traction system. The rail vehicle is not described in
detail herein.
[0088] The embodiments in this specification are described in a
progressive way, each of which emphasizes the differences from
others, and the same or similar parts among the embodiments can be
referred to each other. Since the device disclosed in the
embodiments corresponds to the method therein, the description
thereof is relatively simple, and for relevant matters references
may be made to the description of the method.
[0089] It should be further noted that the relationship
terminologies such as "first", "second" in the present disclosure
are only used herein to distinguish one entity or operation from
another, rather than to necessitate or imply that the actual
relationship or order exists between the entities or operations.
Furthermore, terms of "include", "comprise" or any other variants
are intended to be non-exclusive. Therefore, a process, method,
article or device including multiple components includes not only
the components but also other components that are not enumerated,
or also include the components inherent for the process, method,
article or device. Unless expressively limited otherwise, the
statement "comprising (including) one . . . " does not exclude the
case that other similar components may exist in the process,
method, article or device.
[0090] Based on the above description of the disclosed embodiments,
those skilled in the art can implement or carry out the present
disclosure. It is apparent for those skilled in the art to make
many modifications to these embodiments. The general principle
defined herein may be applied to other embodiments without
departing from the spirit or scope of the present disclosure.
Therefore, the present disclosure is not limited to the embodiments
illustrated herein, but should be defined by the widest scope
consistent with the principle and novel features disclosed
herein.
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